Refrigeration apparatus



c. v. DI PIETRO REFRIGERATION APPARATUS Filed May 31, 1958 2Sheets-Sheet l |N VENTOR A ORNEY Dec. 30, 1941. c. v. DI PIETRO2,267,819

REFRIGERATION APPARATUS Filed May 31, 1958 2 Sheets-Sheet 2 INVENTORTTORNEY Patented Dec. 30, 1941 UNITED STATES PATENT -OFFICEREFRIGERATION APPARATUS Carmelo V. Di Pietro, Birmingham, Mich.Application May 31, 1938, Serial No. 210,807

13 Claims.

This invention relates to heat exchange systems and more particularly tosystems for mechanically refrigerating liquids to be drunk at dispensingstations.

Such systems include a compressor connected to a cooling unit throughwhich the liquid to be dispensed flows under pressure from a source ofsupply to the dispensing faucet. The refrigerating systems are usuallyof the flooded or dry type, and this invention has to do primarily withthe dry type system in which refrigerant is released to the cooling unitin an expanded condition by a thermostatically controlled valve.

It is desirable with many installations that the cooling unit bedisposed adjacent the dispensing faucet in a very limited space, butheretofore this has been impossible because the size of the cooling unitthat would maintain liquid at a desired temperature with rapiddispensing has been prohibitive. The storage space in the cooler and theheat transfer wall area required to maintain a given temperature ofrapidly dispensed liquid during the first part of the compressoroperation in each cycle of operation has necessitated a cooler havingdimensions that have been prohibitive to its use in many installationsin a space adjacent the dispensing faucet.

Installation of the cooling unit remote from the dispensing faucetreduces the efficiency of the system because the temperature of thecooled liquid rises in moving from the cooler to the faucet. In sodafountains, for example. the cooling unit has consisted of coils of abulky nature that have been arranged in one of the food stor agecompartments a considerable distance from the liquid dispensing faucets,thereby reducing the capacity of the storage space in the compartmentand requiring more work by the compressor in maintaining a desiredliquid temperature at the faucet because of the heat picked up by theliquid between the cooler and the faucet.

An object of the invention is to provide a mechanical refrigeratingsystem for liquid to be dispensed at a station with a dry type coolingunit constructed in a manner such that it is small enough to be locatedadjacent the outlet and capable of storing a quantity of cooled liquidsufficient to meet the volume and temperature requirements at thestation between and during the first part of the operating heat transfercycles of the system.

Another object of the invention is to provide a unit for cooling citrusjuices and carbonated water in which the heat transfer elements arejointless and formed of low cost metal that can be plated and readilyinspected prior to assembly.

A further object of the invention is to provide a liquid cooling unitthat minimizes the possibility of damage from freeze-up when therefrigerant control fails to function properly.

It is another object of the invention to provide a mechanicalrefrigeration liquid cooling unit of relatively small dimensions havinga large liquid capacity and designed to maintain the liquid therein in aprogressive path of flow therethrough so that incoming warmer liquidwill not intermingle with the cooled liquid.

A still further object of the invention is to regulate the refrigeratingeffect of a liquid cooler so that the temperature of the dispensedliquid will remain substantially constant with a rela tively high rateof flow.

Another object of the invention is to control the opening and closing ofan expansion valve in a refrigerating system by'thermostat meansresponsive to conditions in both the refrigerant inlet and return linesimmediately adjacent the cooling unit.

Another object of the invention is to provide a cooling unit in amechanical refrigerating sys-- term that will maintain two liquiddispensing systems at the same temperature while utilizing a singleexpansion valve and a single suction pressure control valve.

In=-order that the invention may be clearly understood and readilycarried into effect, it will now be described more fully with referenceto the accompanying drawings, wherein:

Figure 1 is a fragmentary elevational view of a soda fountain, partlybroken away, with a cooling unit incorporating the invention shown inoperating position;

Figure 2 is a vertical sectional view taken on line 2--2 of Fig. 1;

Figure 3 is an end view of a cooling unit for two liquids takenapproximately on line 3-3 of Fig. 1;

Figure 4 is a view, broken away and partly in section, of one of thesections of the cooling unit;

Figure 5 is a longitudinal sectional view through a cooling unitcomprising two sections for cooling two liquids having the remainder ofthe refrigerating system shown diagrammatically;

Figure 6 is an end view of the cooling unit shown in Fig. 5;

Figure 7 is a view partly in elevation and partly in section of a liquidcooling unit composed of one section;

Figure 8 is an elevational view of the cooling unit shown in Figs. 1, 2and 3;

Figure 9 is an enlarged fragmentary end view of the control means inFig. 8;

Figure 10 is a sectional view of th control means taken on line Ill-l ofFigure Figure 11 is a sectional view of the control means taken on linellll of Fig. 5. 1

The refrigerating system forming the subjec matter of this invention isshown installed with a conventional soda fountain, indicated generallyby numeral 20, but the system may be installed equally as well withvarious other types of liquid dispensing stations. Soda fountainsusually consist of a frame having an exterior wall 2| and a wall lining22 of insulating material. The base portion is usually divided intoseparated compartments, the compartment 23 being utilized to storebottled liquids and food requiring a medium low temperature. Theothercompartments are usually utilized for storing ice cream and foodrequiring a low temperature. Access is had to the compartments throughopenings in the rear or top of the base portion, such openings beingclosed by suitable doors or covers 24. Above the forward portion of thebase is an upper structure having a counter top 25 along the frontportion thereof and an enclosed storage space 26 for receiving jars 21adapted to contain fruit syrups and flavoring liquids.

A plurality of liquid dispensing stations are associated with thefountain and two such stations are illustrated. A conduit 28 leads intothe cabinet from a source of drinking water under pressure, not shown,and a conduit 29 leads into the cabinet from a source of carbonatedwater under pressure, not shown. Dispensing arms 30 and 3| extend abovethe fountain top and faucets 32 are associated therewith to controlliquid flow through conduits 50 and 59 leading through the arms.

With such cabinets there is usually associated one or more mechanicalrefrigerating systems each of which employs a compressor 53 andrefrigerant conduits leading to one or more cooling units or evaporatorslocated in the cabinet base compartments. It has been the practice tolead the fluids to be dispensed in heat transfer relation with theevaporator or cooling unit in the storage compartment in which thehighest temperature is maintained. Because of the distance the liquidsmust flow after leaving the cooling unit, their temperature risesconsiderably and hence they must be cooled several degrees below thedesired dispensing temperature. This places more of a burden on thecompressor of the refrigerating system so that efficiency is impairedand when the fluid volume dispensed is rapid, then the temperature ofthe dispensed liquid be comes too high unless the cooler is of largeroverall dimensions. In addition to this, the size of the heat transferunit required to cool the liquid reduces the space available for food orbottle storage in the compartment, and the arrangement furthermorelimits the cooling temperature in the compartment to that required forcooling the dispensable liquids at a desired temperature, usually about40.

These undesirable characteristics and disadvantages encountered withcooling units for cooling dispensed liquids are substantially eliminatedby this invention, wherein a relatively large liquid storage capacityand heat transfer wall area is provided within small dimensions. As aresult, the unit can be arranged close to the dispensing faucet atstations and will deliver the cooled liquid at the desired temperatureeven though the rate of flow is rapid.

The cooling unit, because of its small size, can bearranged in thepreviously wasted space in the jar compartment 26 of a soda fountainand, besides cooling liquid to be dispensed, the exterior surface willserve to cool the jar compartment.

In Figs. 4 and 7 is illustrated a single unit cooler forming the heattransfer portion of the mechanical refrigerating system. It is comprisedof three telescoped tubes 34, 35 and 36 formed of metal having efiicientheat conducting characteristics. The inner tube 34 is preferably formedof stainless steel with a groove extending spirally its entire lengthwhile the tubes 35 and 36 may be formed of brass, aluminum, copper orother material, the tube 35 being provided with a spirally extendingfin. The fin can either be attached to the tube or protruded therefrom,but I prefer to use the protruded fin because there will be no joint,and as it will be absolutely smooth better heat transfer conditionsresult and further, the protruding operation leaves a spiral recess inthe tube. The spiral recess in the tubes 34 and 35 allows for expansionso that there will be less likelihood of a freeze-up rupturing the tubeand will guide the liquid in a spiral progressive path in passingthrough the cooler. The protruded finned tube has the further advantagethat it can be plated more readily and efliciently than tubes on whichthe fin is attached. The contact of citrus juices and carbonated waterwith the lower priced metals creates a chemical reaction that isinjurious to the drinker so these metals must be plated or a moreexpensive metal such as stainless steel employed for this purpose. Withthe present construction this plating with nickel and silver can be doneon the copper tubes before their assembly in the cooling unit so thatinspection can be readily made and as they are jointless the plating isdesirable. Heretofore the constructions of coolers have been such thatthe plating has necessarily been done after assembly of the coolerelements and difliculty of accurate inspection has almost usually forcedthe use of more expensive metal that does not have to be plated, such asstainless steel.

The spiral fin on the tube 35 is formed of a radial dimension so that itcontacts .the inner face of the outer tube 36. Between the two innertubes 34 and 35 is arranged a spirally extending member 38, in the formof a tube as shown in Figs. 4 and '7 and in the form of a rod as shownin Fig. 5. In either case the diameter of member 38 is such that itthermally contacts the adjacent tubes throughout its length. The tubesare fixed at their ends to headers or caps 39 and 40, thus formingbetween the tubes three annular separated compartments or chambers 4|,42 and 43. The inner tube 34 extends through the headers and the endsare suitably secured thereto in leak-proof relation. A fitting 49extends into passage 48 in header 33 and has the conduit 28 fixedthereto, such conduit leads from a supply of water under pressure (notshown). The other end of the chamber 43 connects with a passage 46 inheader 40 and a U-coupling is fixed in this passage and has its otherend fixed in the header 40 in communication with tube 4|. A

fitting 44 extends into header 39 and connects tube 4| with conduit 50leading to arm 3|. A fitting 5| is screwed into the header 40 andcommunicates with the compartment 42, such fitting having a refrigerantconduit 52 connected thereto leading from the compressor 53, shown inFig. 5. Another fitting 54 is screwed into header 39 and communicateswith the compartment 42, such fitting having the refrigerant conduit 55leading to the compressor connected thereto. When the spiral member 38is in the form of a rod, it is of a length to be entirely containedwithin the compartment 34. When the spiral member 38 is in the form of atube, as in Figs. 4 and 7, it can be extended through the headers 39 and46 and a fitting 56 is fixed to one end thereof and has a liquid supplyline 51 connected therewith. To the other end of the tubular spiralmember 38 is fixed a fitting 58 having an outlet line 59 connectedthereto leading to a faucet arm 36 or other dispensing means.

In the refrigerant return line 55 between the compressor and the coolingunit is interposed a conventional form of suction pressure valve 60. Inthe refrigerant supply line 52, between the compressor and the coolingunit, is interposed a conventional form of expansion valve 6| adapted tobe thermostatically controlled. Such valves are shown diagrammaticallyin Fig. 5. The cooling units in Figs. 2 and 4 are shown full size andthe heat transfer surface area and small overall dimensions can bevisualized. In Fig. 7, the outer tube 36 is shown as having a spiral fin62 extending from the outer face thereof, and this form of tube may beutilized when it is desired to transfer a relatively large volume ofheat from the space in which the unit is installed.

In Fig. 5 the cooler is shown as comprising two units A and B, each ofwhich is formed substantially the same as the single unit previouslydescribed. In this form of the invention the headers 40 are connected bya tube 63 having its ends communicating with the refrigerant containingcompartments 42 and the refrigerant inlet fitting is associated with theheader 39 of unit A while the refrigerant outlet fitting is associatedwith the header 39 of unit B. The headers 39 are fixed together bysuitable means, such as tube 65. The refrigerant conduits are connectedwith such fittings and the compressor as previously described. Liquidinlet fittings 44 and 56 are fixed in the header 39 of unit B, fitting44 communicating with compartment 4! and fitting 56 communicating withcompartment 43 of such unit. U-connector tubes 66 and 61 have their endsfixed to the headers 40 of units A and B, the connector 66 communicatingwith compartment 4| in unit A and compartment 43 in unit B whileconnector 61 communicates with compartment 4| in unit B and compartment43 in unit A. Unit A has the two outlet fittings 49 and 58 connected inthe header 39, andconduit 50 leads from fitting 49 to one dispensingstation in arm 3| and conduit 59 leads fromthe fitting 58 to anotherdispensing station in arm 30.

In Figs. 1, 2, 3, and 8 is shown still another form of the inventionparticularly adapted for use with soda fountains. This cooling unit issimilar to that shown in Figs. 5 and 6 and differs therefrom by havingmeans for increasing the through a cooling unit C in returning to thecompressor. In other words, the cooling unit 0 is interposed in thereturn line 65. Such unit 0 is preferably in the form of an externallyfinned tube 86 having an inlet fitting 8| at one end and an outletfitting 82 at the other end, such fittings being connected to sectionsof the return refrigerant line 55. This cooler C is shown placed abovethe units A and B which substantially align vertically, the arrangementbeing such that the complete cooling unit can occupy the formerly wastedspace behind the syrup jars in the compartment 26 with the liquidoutlets in close proximity to the dispensing faucets.

In mechanically refrigerated systems of the dry type for coolingliquids, the bulb of the thermostatic system for actuating the expansionvalve to release refrigerant to the cooler is usually arranged inthermal contact with the refrigerant return line. With such arrangementthe refrigerating system functions only indirectly in response to liquidtemperature and I propose to improve this condition in order to maintaina more even dispensing temperature of the liquid. As best shown in Figs.9 and 10, a bulb of a conventional thermostatic expansion valve controlis in contact with the refrigerant inlet line 52 and with therefrigerant outlet line 55, such relation bein maintained by a metalclamp Ill. The contact is made with the refrigerant supply line betweenthe cooling unit and the expansion valve. In order to further assist inobtaining a more even temperature of dispensed liquid, it is proposed tomake a thermal contact between the beverage inlet conduits and therefrigerant inlet line between the expansion valve and the cooler. Tothis end the refrigerant line is clamped against the liquid supply lines28 and 29 leading to the cooling unit and the refrigerant supply line bya clamp 82, as best shown in Figs. 5 and 11.

The form of cooling unit herein described has many advantages over thosepreviously employed with liquid dispensing systems. As shown by the fullsize views of the units in Figs. 2 and 4, it is obvious that overalldimensions are relatively small so that installation can be made in asmall space. This is important with dispensing stations as it allows theunit to be placed close to the dispenser. Because of its compactness theunit can be located in the normally unoccupied jar space of a sodafountain and close to the dispensing faucets to thereby increase theefllciency of the refrigerating system which must otherwise operateoftener because of temperature rise w-th a more remote installation.Also the location of the unit in a soda fountain allows the spaceformerly occupied in the food storage compartmentto be utilized forfood, and also allows the food storage compartment to be cooled to alower temperature than is possible when the liquid cooling unit islocated in such compartment. The unit also will displace other coolingmeans in the jar space of a fountain and when the outer tube is finnedthen of course a greater heat transfer from the jar compartment results.The heat-is transferred from the space in which the unit is installedthrough the outer tube and the finned intermediate tube to therefrigerant, the contact of the fins 3-1 with the outer tubeservingielficiently for this purpose.

The spiral recesses in the two inner tubes of the cooling unit provideadditional heat transfer surfaces as compared with plain tubes, theyassist in moving the liquids progressively through the cooler, and theyreduce the hazard of a freeze-up upon failure of the suction controlvalve as they will allow greater liquid expansion without bursting thetubes. As before related, these tubes can be plated and accuratelyinspected before assembly so that they can be formed of low pricedmaterial, and the protruded fin allows smooth and accurate plating andmaximum heat transfer. The elements of the cooling unit can befabricated at low cost and readily assembled. The spiral fin on theintermediate tube gives a large heat transfer wall area and serves toguide the liquid in a progressive path of travel so that the incomingwarmer liquid does not mingle with water already cooled in the storagechamber, thereby preventing the heating of the cold water. The largestorage capacity of the cooler serves to aid the maintenance of definiteexit beverage temperature.

Through means of the extensive wall area of the relatively small unitand the large liquid storage capacity thereof, there will be suilicientcooled liquid to meet the demands of the dispensing station, even whenthe flow is rapid, while the refrigerating system lags in itsrefrigerating ability at the first part of the operating cycles. Thecooler controls both the refrigerant and liquid flow in a manner toprovide an even dispensing temperature for the liquid although theoverall dimensions are relatively small.

The liquid moves partly in an opposite direction to the refrigerant flowin the single cooler while in the double unit the liquids and therefrigerant flow entirely in opposite directions through the cooler.With this arrangement of the two unitsfi a plurality of liquids can becooled and dispensed at an even temperature in a manner that requiresonly one expansion valve and one suction pressure control valve.

Various changes can be made in the embodiments of the invention asherein shown and described without departing from the spirit of theinvention and the scope of the following claims.

What I claim is:

1. A liquid cooler comprising two tubes telescopically associated toform two separate closed chambers, a refrigerating system connected withthe outer chamber, a dispensing drinking liquid system connected withthe inner chamber, a tube extending spirally in the outer refrigerantchamber, said spirally extending tube thermally contacting saidtelescopically associated tubes and defining therewith a spiralrefrigerant passageway through the outer chamber, and a liquiddispensing system connected with the interior of the spirally extendingtube.

2. A liquid cooler comprising two sets of three telescoped tubes, thetubes of each set being associated to form three separate chambers,means connecting the outer chamber of one of a first set in series withthe inner chamber of the second set of chambers, means connecting theinner chamber of the first set in series with the outer chamber of thesecond set, a connection between the intermediate chambers of the sets,a refrigerating system connected with the intermediate chambers, and twodispensing fluid systems connected one with each series of connectedchambers.

3. A liquid cooler comprising two sets of three telescoped tubes, thetubes of each set being associated to form three chambers, an endconnection between the intermediate chambers of said sets of tubes, arefrigerant line leading into one of the intermediate chambers at theend opposite the connection, a refrigerant line leading from the otherintermediate chamber at the end opposite the connection, connectionsadjacent said refrigerant connector between the outer chamber of one setand the inner chamber of the other set. two liquid inlet lines connectedwith the end of one set remote from the connectors, one of said linescommunicating with the inner chamber and the other with the outerchamber, and two liquid outlet lines connected with the end of the otherset remote from the connectors, one of said outlet lines communicatingwith the inner chamber and the other outlet line communicating with theouter chamber, the liquids flowing through the cooler inthe oppositedirection to the refrigerant flow.

4. A liquid cooler comprising three telescoped tubes forming threeseparate chambers, a refrigerant line connected to the intermediatechamber, liquid lines connected with the inner and outer chambers, andspirally coiled tubing in the refrigerant chamber in thermal contactwith the tubes forming the chamber, and a liquid line connected withsaid spiralled tubing.

5. A liquid cooler comprising three telescoped tubes forming threechambers, refrigerant inlet and outlet lines connected to opposite endsof the intermediate chamber, liquid connections with the inner and outerchambers, and an externally finned heat transfer chamber connected inthe refrigerant outlet line.

6. A liquid cooling unit comprising a set of three spaced telescopedtubes, a header at each end of said set, a connection adjacent one ofthe headers directly joining the inner and outer spaces formed by thetubes, inlet and outlet liquid connections leading to the said inner andouter spaces through the other header, and a refrigerant inlet andoutlet open to the intermediate space formed by the tubes.

7. A liquid cooler comprising two telescoped tubes forming two chambers,one of said tubes being formed with a spiral groove extending axiallythereof, means connected with the chamber in which the groove opens topass drinking liquid therethrough, and a refrigerating system .lineconnected with the other chamber.

8. A liquid cooler comprising three telescoped tubes forming threeseparate chambers, a refrigerant line connected to the intermediatechamber, spirally coiled tubing in the intermediate chamber, anddrinking liquid dispensing means connected with the inner and outerchambers and with the spirally coiled tubing.

9. A liquid cooler comprising three telescoped tubes forming threechambers, drinking liquid dispensing means connected with the inner andouter chambers, a heat transfer chamber connected with the intermediatechamber out of thermal contact with the other chambers, and arefrigerating system connected withthe intermediate chamber and heattransfer chamber.

10. A liquid cooler comprising two telescoped tubes forming two separatechambers, the inner tube having a spiral groove formed in the inner wallsurface thereof, means thermally contacting the tubes, a refrigeratingsystem connected to the outer chamber, and a drinking liquid dispensingsystem connected to the inner chamber.

11. A liquid cooler comprising three coextensive telescoped tubes closedat their ends and forming three chambers, a mechanical refrigeratingsystem connected with the ends of the intermediate chamber, means insaid intermediate and outer chambers in thermal contact with theadjacent tubes and forming therewith spiral passages, means connectingthe ends of th inner and outer chambers adjacent the refrigerant inletend of the intermediate chamber, and a source of drinking fluid underpressure connected to the inner and outer chambers with the inlet andthe outlet at the ends adjacent the refrigerant outlet end of theintermediate chamber, the flow of liquid being through the spiralpassages and in opposite directions through the inner and outerchambers.

12. A liquid cooler comprising a plurality of tubes forming threeco-extensive chambers, heat transfer means in the two outer chambersthermally contacting the tubes forming such chambers throughout theirlength, means connecting the intermediate chamber with a mechanicalrefrigerating system, means directly connecting one end of the inner andouter chambers, a supply line for drinking liquid under pressure leadinginto one of the connected chambers, and a drinking liquid outlet lineleading from the other of the connected chambers, the inlet and outletlines for the liquid being at adjacent ends of the chambers with whichthey are connected.

13. A liquid cooling device comprising two telescopically associatedtubes forming two separate chambers, means attached to the ends of thetubes for closing the chambers, a refrigerating system connected withthe outer chamber through the closing means, a dispensing drinkingliquid system connected with the inner chamber through the closuremeans, a tube extending spirally through the outer chamber, and a liquiddispensing system through the closure means with the spirally extendingtube.

. CARMELO V..DI PIEI'RO.

